An intercept of Syrian military officials discussing the strike was among low-level staff, with no direct evidence tying the attack back to an Assad insider or even a senior Syrian commander, the officials said.

So while Secretary of State John Kerry said Monday that links between the attack and the Assad government are “undeniable,” U.S. intelligence officials are not so certain that the suspected chemical attack was carried out on Assad’s orders, or even completely sure it was carried out by government forces, the officials said.

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Another possibility that officials would hope to rule out: that stocks had fallen out of the government’s control and were deployed by rebels in a callous and calculated attempt to draw the West into the war.

In other words, the U.S. hasn’t yet ruled out that possibility … but only hopes to.

American officials said Wednesday there was no “smoking gun” that directly links President Bashar al-Assad to the attack

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It appears that the public presentation of the Syria evidence will be limited. Instead of the theater of Mr. Powell’s 2003 speech — which included satellite photographs, scratchy recordings of conversations between Iraqi officials and a vial of white powder meant to symbolize anthrax — American officials said the intelligence assessment they are preparing to make public will be similar to a modest news release that the White House issued in June to announce that the Assad government had used chemical weapons “on a small scale against the opposition multiple times in the last year.”